Searching for compatible electrolytes with Ni_(0.8)C_(00.15)Al_(0.05)LiO_(2-δ)(NCAL)electrodes that exhibit high ionic conductivity at low operational temperatures(<550℃)is crucial for advancing ceramics fuel cel...Searching for compatible electrolytes with Ni_(0.8)C_(00.15)Al_(0.05)LiO_(2-δ)(NCAL)electrodes that exhibit high ionic conductivity at low operational temperatures(<550℃)is crucial for advancing ceramics fuel cells(CFCs)research.In this work,the experimental and theoretical analyses demonstrate that the highly stable single-phase Gd_(3)Ga_(5)O_(12)(GGO)garnet structure,composed of Gd-O octahedrons and Ga-O tetrahedrons,provides more active sites for ion transport,resulting in enhanced peak power density(PPD)and stable open circuit voltage(OCV)at low operational temperatures.The unique internal garnet structure effectively reduces the interfacial impedance of the prepared fuel cell device,provides more active sites at triple-phase boundarie region,and increases the electrochemical stability.As a result,the constructed fuel cell device can deliver a superior peak power density of 770 mW/cm^(2)at 490℃.In addition,X-ray photoelectron spectroscopy,electrochemical impedance spectroscopy,and theoretical calculations further demonstrate electrolyte effectiveness of GGO,enabling stable an OCV even at a low temperature of 370℃under a H_(2)/air environment.This work contributes to a deeper understanding of the underlying mechanisms of a single-layer fuel cell device,which is essential for advancing this promising energy technology,even at a very low temperature of 370℃.展开更多
Along with the surging demand for energy storage devices,the cost and availability of the materials remain dominant factors in slowing down their industrial application.The repurposing of waste asphalt into high-perfo...Along with the surging demand for energy storage devices,the cost and availability of the materials remain dominant factors in slowing down their industrial application.The repurposing of waste asphalt into high-performance electrode materials is of significant interest,as it holds the potential to circumvent energy and environmental issues.Here,we report the controllable synthesis of asphalt-derived mesoporous carbon as an active material for electrocatalytic hydrogen gas capacitor(EHGC).The hierarchically porous carbon(HPC)with a high surface area of 1943.4 m^(2)·g^(-1)can operate in pH universal aqueous electrolytes in EHGC.It displays a specific energy and power density of 57 Wh·kg^(-1)and 554 W·kg^(-1)in neutral electrolyte as well as 52 Wh·kg^(-1)and 657 W·kg^(-1)in acidic electrolyte.Additionally,the charge storage mechanism of HPC-EHGC is studied with the help of Raman spectroscopy and X-ray photoelectron spectroscopy.Furthermore,the assembled HPC-EHGC device displays a discharge capacitance of 170 F·g^(-1)with an excellent capacitance retention rate of 100%up to 20000 cycles at 10 A·g^(-1)in acidic electrolyte.This work introduces a novel approach to converting waste asphalt into high-performance carbon for EHGC,achieving superior performance over commercial materials.By simultaneously addressing environmental waste issues and advancing energy storage technology,this study makes a significant contribution to sustainable materials science and next-generation battery development.展开更多
Al7075-Cu composite joints were prepared by the squeeze overcast process.The effects of melt temperature,die temperature,and squeeze pressure on hardness and ultimate tensile strength(UTS)of squeeze overcast Al7075-Cu...Al7075-Cu composite joints were prepared by the squeeze overcast process.The effects of melt temperature,die temperature,and squeeze pressure on hardness and ultimate tensile strength(UTS)of squeeze overcast Al7075-Cu composite joints were studied.The experimental results depict that squeeze pressure is the most significant process parameter affecting the hardness and UTS.The optimal values of UTS(48 MPa)and hardness(76 HRB)are achieved at a melt temperature of 800℃,a die temperature of 250℃,and a squeeze pressure of 90 MPa.Scanning electron microscopy(SEM)shows that fractured surfaces show flatfaced morphology at the optimal experimental condition.Energy-dispersive spectroscopy(EDS)analysis depicts that the atomic weight percentage of Zn decreases with an increase in melt temperature and squeeze pressure.The optimal mechanical properties of the Al7075-Cu overcast joint were achieved at the Al2Cu eutectic phase due to the large number of copper atoms that dispersed into the aluminum melt during the solidification process and the formation of strong intermetallic bonds.Gray relational analysis integrated with the Taguchi method was used to develop an optimal set of control variables for multi-response parametric optimization.Confirmatory tests were performed to validate the effectiveness of the employed technique.The manufacturing of squeeze overcast Al7075-Cu composite joints at optimal process parameters delivers a great indication to acknowledge a new method for foundry practitioners to manufacture materials with superior mechanical properties.展开更多
Field trials were conducted to evaluate the epidemiological factors of okra yellow vein mosaic virus (OYVMV). Four varieties of okra were subjected to screening and evaluation of the chemicals. The variety Saloni F1 w...Field trials were conducted to evaluate the epidemiological factors of okra yellow vein mosaic virus (OYVMV). Four varieties of okra were subjected to screening and evaluation of the chemicals. The variety Saloni F1 was highly resistant while Subz Pari was moderately resistant. Diksha was the tolerant variety while Lush Green was moderately susceptible. The chemical Imidacloprid was most effective to control whitefly population and okra yellow vein mosaic virus (OYVMV). Correlation of environmental factors (maximum and minimum temperature, relative humidity and rainfall) with percent plant infection of okra yellow vein mosaic virus (OYVMV) was also determined. There was a significant correlation between environment and disease severity.展开更多
The granitic rocks around the Utla area（Gadoon）, north western, Pakistan are studied in terms of their petrographic features and geochemical characteristics. Although predominantly mega-porphyritic, some of the Utla...The granitic rocks around the Utla area（Gadoon）, north western, Pakistan are studied in terms of their petrographic features and geochemical characteristics. Although predominantly mega-porphyritic, some of the Utla granites are massive and display fine-grained equi-granular texture. Some of the mega-porphyritic varieties exhibit foliation and seem to be restricted to shear zones. In addition to being distributed largely as phenocrysts, all the essential minerals（plagioclase, perthitic alkali feldspar and quartz） also constitute the groundmass. The studied samples also contain minor to accessory amounts of tourmaline, muscovite and biotite and accessory to trace amounts of apatite, andalusite, garnet, zircon, monazite, epidote and sphene. A detailed geochemical investigation reveals a calc-alkaline and peraluminous character of the Utla granites. The peraluminous character and total lack of hornblende designate their S-type character while a volcanic arc or syn-collisional tectonic setting for their emplacement is indicated by discrimination diagrams. Further examination shows that the melt parental to the Utla granite was derived from a plagioclase-poor, clay-rich rock, i.e., pelite. The petrogenetically significant petrographic and geochemical features of the Utla granite show greater similarity with the Mansehra than the Ambela granites. These include（i） the predominantly megaporphyritic texture,（ii） the presence of andalusite and tourmaline,（iii） the calc-alkaline geochemical signature and（iv） an indication of similar melt source rock character.展开更多
Seventy percent of new product cost is committed in the design phase. Therefore, the cost needs to be minimized. Incorporating accurate cost estimation capabilities into manufacturing processes can help industries to ...Seventy percent of new product cost is committed in the design phase. Therefore, the cost needs to be minimized. Incorporating accurate cost estimation capabilities into manufacturing processes can help industries to minimize the cost and optimize the design. The casting process has been employed as a key process to manufacture parts having the advantage of low cost and customized products in foundry industry. This paper presents a cost estimation system for the casting process based on the design features, which incorporates the casting information at the design stage of castings. It aims to deliver the best cost-effective choice for casting design features of a product. Two kinds of knowledge, namely economical knowledge(describing the relation between the casting design considerations and the cost) and technical knowledge(involving the material of the casting features) were structured in this research work. On the basis of the minimum product cost, casting material selection can be carried out in detail. The developed system has been validated through an industrial case study.展开更多
We investigate the evolution of a discrete-time one-dimensional quantum walk driven by a position-dependent coin.The rotation angle,which depends upon the position of a quantum particle,parameterizes the coin operator...We investigate the evolution of a discrete-time one-dimensional quantum walk driven by a position-dependent coin.The rotation angle,which depends upon the position of a quantum particle,parameterizes the coin operator.For different values of the rotation angle,we observe that such a coin leads to a variety of probability distributions,e.g.localized,periodic,classicallike,semi-classical-like,and quantum-like.Further,we study the Shannon entropy associated with position and the coin space of a quantum particle,and compare them with the case of the position-independent coin.Our results show that the entropy is smaller for most values of the rotation angle as compared to the case of the position-independent coin.We also study the effect of entanglement on the behavior of probability distribution and Shannon entropy by considering a quantum walk with two identical position-dependent entangled coins.We observe that in general,a wave function becomes more localized as compared to the case of the positionindependent coin and hence the corresponding Shannon entropy is lower.Our results show that a position-dependent coin can be used as a controlling tool of quantum walks.展开更多
Wheat is a strategic crop for food security in Pakistan with predominance of smallholder farmers. Farmer-saved seed （FSS） is used nearly by 75% of farmers for wheat production. Frequent variety or seed replacement i...Wheat is a strategic crop for food security in Pakistan with predominance of smallholder farmers. Farmer-saved seed （FSS） is used nearly by 75% of farmers for wheat production. Frequent variety or seed replacement is uncommon even among large-scale farmers, and certified seed （CS） is mostly bought to verify the value of new varieties. Replacing old and obsolete varieties by new high yielding disease resistant varieties is key to transferring new genetic gains to farmers. For the first time in Pakistan, on-farm factorial experiments involving seven new and five old wheat varieties and their corresponding CS and FSS were conducted. A total of 49 farmers representing major wheat cropping patterns throughout the country participated in these trials in the 2014 and 2015 wheat growing seasons. Analysis of variance revealed that there was highly significant difference between wheat varieties and between seed classes. New variety ＋ CS gave 33.8% more grain yield as well as higher marginal return over farmers＇ variety ＋ FSS. Grain yield and returns from new variety ＋ FSS and farmers＇ variety ＋ CS were at par. Scientific knowledge generated in this research demonstrated that use of CS ＆new wheat varieties is best option, while growing new varieties with FSS is a second choice for the advantages accruing from their built-in genetic traits of economic importance over growing CS of old and obsolete varieties. Having more flexible seed system will help accelerate the delivery of new genetic gains to farmers＇ fields.展开更多
Physico-chemical composition of sweet orange （Citrus sinensis L.） cv. blood red was determined in relation to different storage conditions and micronutrients application at department of horticulture, Agricultural U...Physico-chemical composition of sweet orange （Citrus sinensis L.） cv. blood red was determined in relation to different storage conditions and micronutrients application at department of horticulture, Agricultural University Peshawar, Pakistan during 2006-2007 and 2007-2008. The post-harvest quality of sweet orange was evaluated for 60 days storage with 20 days intervals. Fruit were harvested after the foliar application of zinc and boron in two consecutive seasons. The harvested fruits were stored at an ambient temperature （ATS） of 25 ＋ 2 ℃ and at low temperature storage （LTS） of 15 ± 2 ℃ with 60%-70% relative humidity （RH） for 60 days. Sweet oranges stored at LTS maintained better fruit quality than ATS. The foliar application of zinc and boron significantly enhanced fruit juice content, total soluble solids （TSS）, ascorbic acid （AA） and non-reducing sugar （NRS） of fruit. However, fruit juice content, TSS and AA were observed significantly higher, when the fruit was treated with high zinc （1%） and low boron （0.02%）. The percent of weight loss, disease incidence, TSS and reducing sugar （RS） increased with increasing the storage durations. A reduction was noted in fruit juice, AA and NRS with increasing the storage durations.展开更多
Petrographic and geo-mechanical properties of samples representing quartzose rocks of Tanawal Formation (Baja Bamkhel area, Swabi) and Misri Banda quartzite (Nowshera) from Peshawar Basin, NW Pakistan, have been inves...Petrographic and geo-mechanical properties of samples representing quartzose rocks of Tanawal Formation (Baja Bamkhel area, Swabi) and Misri Banda quartzite (Nowshera) from Peshawar Basin, NW Pakistan, have been investigated. Although formerly referred to as quartzite, mineralogical composition and textural details support characterization of the studied quartzose samples of Tanawal Formation as blasto-psammite and those of Misri Banda as sub-arkose. The two rock types also show significant differences in terms of matrix and heavy mineral concentrations as well as the degree and frequency of intra-granular deformation. On the basis of unconfined compressive strength (UCS), both fall in the category of very strong rocks. Correspondingly, their specific gravity and water absorption values are high and low respectively and lie well within the range permissible for use as construction material. However, both contain high amounts of deleterious components, i.e. reactive forms of silica (chert and/or strained quartz) and clay minerals. Therefore, they cannot be used as coarse aggregate with Ordinary Portland Cement (OPC) and asphalt. The modal abundance of quartz is higher in the Misri Banda than the Tanawal samples, but the quartz to feldspar ratios are higher for the latter. Yet, the sub-arkosic Misri Banda rocks are stronger than the Tanawal blasto-psammites, most probably because they are i) almost totally devoid of matrix;ii) finer grained;iii) having a higher percentage of grains with irregular and sutured contacts and iv) lesser abundance of grains displaying intra-granular deformation.展开更多
Climate change can adversely impact the thermal comfort and energy efficiency of the buildings stock. The South Asian countries are particularly vulnerable to the adverse impacts of climate change specially in the for...Climate change can adversely impact the thermal comfort and energy efficiency of the buildings stock. The South Asian countries are particularly vulnerable to the adverse impacts of climate change specially in the form of rising temperatures and increasing frequency of heat waves. The passive building design measures can be useful in mitigating and adapting to the climate change by increasing energy efficiency and reducing greenhouse gas (GHG) emissions. In this study various passive climate change adaptation measures (PCAMs) have been used individually and in form of combinations in order to analyze their impact on the energy efficacy of residential buildings in Pakistan. It has been found that the natural ventilation and front green wall are the most efficient options for reducing the overall energy consumption. By implementation of these PCAMs, cooling demand can be decreased by 27.75% while heating demand can be reduced by 35%. Secondly, the prospect of net zero-energy building and reduced CO2 emissions are also studied. It has been shown that building can achieve net-zero energy on an annual basis at every orientation and it can attain the status of nearly zero-energy building on a monthly basis. Moreover, emitted CO2 can be reduced by 31% by using the renewable energy.展开更多
Semiconductors and the associated methodologies applied to electrochemistry have recently grown as an emerging field in energy materials and technologies.For example,semiconductor membranes and heterostructure fuel ce...Semiconductors and the associated methodologies applied to electrochemistry have recently grown as an emerging field in energy materials and technologies.For example,semiconductor membranes and heterostructure fuel cells are new technological trend,which differ from the traditional fuel cell electrochemistry principle employing three basic functional components:anode,electrolyte,and cathode.The electrolyte is key to the device performance by providing an ionic charge flow pathway between the anode and cathode while preventing electron passage.In contrast,semiconductors and derived heterostructures with electron(hole)conducting materials have demonstrated to be much better ionic conductors than the conventional ionic electrolytes.The energy band structure and alignment,band bending and built-in electric field are all important elements in this context to realize the necessary fuel cell functionalities.This review further extends to semiconductor-based electrochemical energy conversion and storage,describing their fundamentals and working principles,with the intention of advancing the understanding of the roles of semiconductors and energy bands in electrochemical devices for energy conversion and storage,as well as applications to meet emerging demands widely involved in energy applications,such as photocatalysis/water splitting devices,batteries and solar cells.This review provides new ideas and new solutions to problems beyond the conventional electrochemistry and presents new interdisciplinary approaches to develop clean energy conversion and storage technologies.展开更多
With the disruptive carbon cycle being blamed for global warming,the plausible electrocatalytic CO_(2)reduction reaction(CO_(2)RR)to form valuable C_(2+)hydrocarbons and feedstock is becoming a hot topic.Cu-based elec...With the disruptive carbon cycle being blamed for global warming,the plausible electrocatalytic CO_(2)reduction reaction(CO_(2)RR)to form valuable C_(2+)hydrocarbons and feedstock is becoming a hot topic.Cu-based electrocatalysts have been proven to be excellent CO_(2)RR alternatives for high energy value-added products in this regard.However,the selectivity of CO_(2)RR to form C_(2+)products via Cu-based catalysts suffers from a high overpotential,slow reaction kinetics,and low selectivity.This review attempts to discuss various cutting-edge strategies for understanding catalytic design such as Cu-based catalyst surface engineering,tuning Cu bandgap via alloying,nanocatalysis,and the effect of the electrolyte and pH on catalyst morphology.The most recent advances in in situ spectroscopy and computational techniques are summarized to fully comprehend reaction mechanisms,structural transformation/degradation mechanisms,and crystal facet loss with subsequent effects on catalyst activity.Furthermore,approaches for tuning Cu interactions are discussed from four key perspectives:single-atom catalysts,interfacial engineering,metal-organic frameworks,and polymer-incorporated materials,which provide new insights into the selectivity of C_(2+)products.Finally,major challenges are outlined,and potential prospects for the rational design of catalysts for robust CO_(2)RR are proposed.The integration of catalytic design with mechanistic understanding is a step forward in the promising advancement of CO_(2)RR technology for industrial applications.展开更多
基金supported by the Jiangsu Fundamental Research Program(JSSCRC2021491)Ongoing Research Funding Program(ORF-2025-391)。
文摘Searching for compatible electrolytes with Ni_(0.8)C_(00.15)Al_(0.05)LiO_(2-δ)(NCAL)electrodes that exhibit high ionic conductivity at low operational temperatures(<550℃)is crucial for advancing ceramics fuel cells(CFCs)research.In this work,the experimental and theoretical analyses demonstrate that the highly stable single-phase Gd_(3)Ga_(5)O_(12)(GGO)garnet structure,composed of Gd-O octahedrons and Ga-O tetrahedrons,provides more active sites for ion transport,resulting in enhanced peak power density(PPD)and stable open circuit voltage(OCV)at low operational temperatures.The unique internal garnet structure effectively reduces the interfacial impedance of the prepared fuel cell device,provides more active sites at triple-phase boundarie region,and increases the electrochemical stability.As a result,the constructed fuel cell device can deliver a superior peak power density of 770 mW/cm^(2)at 490℃.In addition,X-ray photoelectron spectroscopy,electrochemical impedance spectroscopy,and theoretical calculations further demonstrate electrolyte effectiveness of GGO,enabling stable an OCV even at a low temperature of 370℃under a H_(2)/air environment.This work contributes to a deeper understanding of the underlying mechanisms of a single-layer fuel cell device,which is essential for advancing this promising energy technology,even at a very low temperature of 370℃.
基金financially supported by the National Natural Science Foundation of China(Nos.92372122 and 52471242)the Fundamental Research Funds for the Central Universities,China(Nos.GG2060127001,KY2060000150,and WK2060000040)supported by the Joint Laboratory for USTC and Yanchang Petroleum,China(No.2022ZK-03)。
文摘Along with the surging demand for energy storage devices,the cost and availability of the materials remain dominant factors in slowing down their industrial application.The repurposing of waste asphalt into high-performance electrode materials is of significant interest,as it holds the potential to circumvent energy and environmental issues.Here,we report the controllable synthesis of asphalt-derived mesoporous carbon as an active material for electrocatalytic hydrogen gas capacitor(EHGC).The hierarchically porous carbon(HPC)with a high surface area of 1943.4 m^(2)·g^(-1)can operate in pH universal aqueous electrolytes in EHGC.It displays a specific energy and power density of 57 Wh·kg^(-1)and 554 W·kg^(-1)in neutral electrolyte as well as 52 Wh·kg^(-1)and 657 W·kg^(-1)in acidic electrolyte.Additionally,the charge storage mechanism of HPC-EHGC is studied with the help of Raman spectroscopy and X-ray photoelectron spectroscopy.Furthermore,the assembled HPC-EHGC device displays a discharge capacitance of 170 F·g^(-1)with an excellent capacitance retention rate of 100%up to 20000 cycles at 10 A·g^(-1)in acidic electrolyte.This work introduces a novel approach to converting waste asphalt into high-performance carbon for EHGC,achieving superior performance over commercial materials.By simultaneously addressing environmental waste issues and advancing energy storage technology,this study makes a significant contribution to sustainable materials science and next-generation battery development.
文摘Al7075-Cu composite joints were prepared by the squeeze overcast process.The effects of melt temperature,die temperature,and squeeze pressure on hardness and ultimate tensile strength(UTS)of squeeze overcast Al7075-Cu composite joints were studied.The experimental results depict that squeeze pressure is the most significant process parameter affecting the hardness and UTS.The optimal values of UTS(48 MPa)and hardness(76 HRB)are achieved at a melt temperature of 800℃,a die temperature of 250℃,and a squeeze pressure of 90 MPa.Scanning electron microscopy(SEM)shows that fractured surfaces show flatfaced morphology at the optimal experimental condition.Energy-dispersive spectroscopy(EDS)analysis depicts that the atomic weight percentage of Zn decreases with an increase in melt temperature and squeeze pressure.The optimal mechanical properties of the Al7075-Cu overcast joint were achieved at the Al2Cu eutectic phase due to the large number of copper atoms that dispersed into the aluminum melt during the solidification process and the formation of strong intermetallic bonds.Gray relational analysis integrated with the Taguchi method was used to develop an optimal set of control variables for multi-response parametric optimization.Confirmatory tests were performed to validate the effectiveness of the employed technique.The manufacturing of squeeze overcast Al7075-Cu composite joints at optimal process parameters delivers a great indication to acknowledge a new method for foundry practitioners to manufacture materials with superior mechanical properties.
文摘Field trials were conducted to evaluate the epidemiological factors of okra yellow vein mosaic virus (OYVMV). Four varieties of okra were subjected to screening and evaluation of the chemicals. The variety Saloni F1 was highly resistant while Subz Pari was moderately resistant. Diksha was the tolerant variety while Lush Green was moderately susceptible. The chemical Imidacloprid was most effective to control whitefly population and okra yellow vein mosaic virus (OYVMV). Correlation of environmental factors (maximum and minimum temperature, relative humidity and rainfall) with percent plant infection of okra yellow vein mosaic virus (OYVMV) was also determined. There was a significant correlation between environment and disease severity.
文摘The granitic rocks around the Utla area（Gadoon）, north western, Pakistan are studied in terms of their petrographic features and geochemical characteristics. Although predominantly mega-porphyritic, some of the Utla granites are massive and display fine-grained equi-granular texture. Some of the mega-porphyritic varieties exhibit foliation and seem to be restricted to shear zones. In addition to being distributed largely as phenocrysts, all the essential minerals（plagioclase, perthitic alkali feldspar and quartz） also constitute the groundmass. The studied samples also contain minor to accessory amounts of tourmaline, muscovite and biotite and accessory to trace amounts of apatite, andalusite, garnet, zircon, monazite, epidote and sphene. A detailed geochemical investigation reveals a calc-alkaline and peraluminous character of the Utla granites. The peraluminous character and total lack of hornblende designate their S-type character while a volcanic arc or syn-collisional tectonic setting for their emplacement is indicated by discrimination diagrams. Further examination shows that the melt parental to the Utla granite was derived from a plagioclase-poor, clay-rich rock, i.e., pelite. The petrogenetically significant petrographic and geochemical features of the Utla granite show greater similarity with the Mansehra than the Ambela granites. These include（i） the predominantly megaporphyritic texture,（ii） the presence of andalusite and tourmaline,（iii） the calc-alkaline geochemical signature and（iv） an indication of similar melt source rock character.
基金supported by KSB Pumps,Hassanabdal,Pakistanfunded by Directorate of Advanced Studies Research and Technological Development(ASR&TD)University of Engineering and Technology Taxila,Pakistan
文摘Seventy percent of new product cost is committed in the design phase. Therefore, the cost needs to be minimized. Incorporating accurate cost estimation capabilities into manufacturing processes can help industries to minimize the cost and optimize the design. The casting process has been employed as a key process to manufacture parts having the advantage of low cost and customized products in foundry industry. This paper presents a cost estimation system for the casting process based on the design features, which incorporates the casting information at the design stage of castings. It aims to deliver the best cost-effective choice for casting design features of a product. Two kinds of knowledge, namely economical knowledge(describing the relation between the casting design considerations and the cost) and technical knowledge(involving the material of the casting features) were structured in this research work. On the basis of the minimum product cost, casting material selection can be carried out in detail. The developed system has been validated through an industrial case study.
文摘We investigate the evolution of a discrete-time one-dimensional quantum walk driven by a position-dependent coin.The rotation angle,which depends upon the position of a quantum particle,parameterizes the coin operator.For different values of the rotation angle,we observe that such a coin leads to a variety of probability distributions,e.g.localized,periodic,classicallike,semi-classical-like,and quantum-like.Further,we study the Shannon entropy associated with position and the coin space of a quantum particle,and compare them with the case of the position-independent coin.Our results show that the entropy is smaller for most values of the rotation angle as compared to the case of the position-independent coin.We also study the effect of entanglement on the behavior of probability distribution and Shannon entropy by considering a quantum walk with two identical position-dependent entangled coins.We observe that in general,a wave function becomes more localized as compared to the case of the positionindependent coin and hence the corresponding Shannon entropy is lower.Our results show that a position-dependent coin can be used as a controlling tool of quantum walks.
文摘Wheat is a strategic crop for food security in Pakistan with predominance of smallholder farmers. Farmer-saved seed （FSS） is used nearly by 75% of farmers for wheat production. Frequent variety or seed replacement is uncommon even among large-scale farmers, and certified seed （CS） is mostly bought to verify the value of new varieties. Replacing old and obsolete varieties by new high yielding disease resistant varieties is key to transferring new genetic gains to farmers. For the first time in Pakistan, on-farm factorial experiments involving seven new and five old wheat varieties and their corresponding CS and FSS were conducted. A total of 49 farmers representing major wheat cropping patterns throughout the country participated in these trials in the 2014 and 2015 wheat growing seasons. Analysis of variance revealed that there was highly significant difference between wheat varieties and between seed classes. New variety ＋ CS gave 33.8% more grain yield as well as higher marginal return over farmers＇ variety ＋ FSS. Grain yield and returns from new variety ＋ FSS and farmers＇ variety ＋ CS were at par. Scientific knowledge generated in this research demonstrated that use of CS ＆new wheat varieties is best option, while growing new varieties with FSS is a second choice for the advantages accruing from their built-in genetic traits of economic importance over growing CS of old and obsolete varieties. Having more flexible seed system will help accelerate the delivery of new genetic gains to farmers＇ fields.
文摘Physico-chemical composition of sweet orange （Citrus sinensis L.） cv. blood red was determined in relation to different storage conditions and micronutrients application at department of horticulture, Agricultural University Peshawar, Pakistan during 2006-2007 and 2007-2008. The post-harvest quality of sweet orange was evaluated for 60 days storage with 20 days intervals. Fruit were harvested after the foliar application of zinc and boron in two consecutive seasons. The harvested fruits were stored at an ambient temperature （ATS） of 25 ＋ 2 ℃ and at low temperature storage （LTS） of 15 ± 2 ℃ with 60%-70% relative humidity （RH） for 60 days. Sweet oranges stored at LTS maintained better fruit quality than ATS. The foliar application of zinc and boron significantly enhanced fruit juice content, total soluble solids （TSS）, ascorbic acid （AA） and non-reducing sugar （NRS） of fruit. However, fruit juice content, TSS and AA were observed significantly higher, when the fruit was treated with high zinc （1%） and low boron （0.02%）. The percent of weight loss, disease incidence, TSS and reducing sugar （RS） increased with increasing the storage durations. A reduction was noted in fruit juice, AA and NRS with increasing the storage durations.
文摘Petrographic and geo-mechanical properties of samples representing quartzose rocks of Tanawal Formation (Baja Bamkhel area, Swabi) and Misri Banda quartzite (Nowshera) from Peshawar Basin, NW Pakistan, have been investigated. Although formerly referred to as quartzite, mineralogical composition and textural details support characterization of the studied quartzose samples of Tanawal Formation as blasto-psammite and those of Misri Banda as sub-arkose. The two rock types also show significant differences in terms of matrix and heavy mineral concentrations as well as the degree and frequency of intra-granular deformation. On the basis of unconfined compressive strength (UCS), both fall in the category of very strong rocks. Correspondingly, their specific gravity and water absorption values are high and low respectively and lie well within the range permissible for use as construction material. However, both contain high amounts of deleterious components, i.e. reactive forms of silica (chert and/or strained quartz) and clay minerals. Therefore, they cannot be used as coarse aggregate with Ordinary Portland Cement (OPC) and asphalt. The modal abundance of quartz is higher in the Misri Banda than the Tanawal samples, but the quartz to feldspar ratios are higher for the latter. Yet, the sub-arkosic Misri Banda rocks are stronger than the Tanawal blasto-psammites, most probably because they are i) almost totally devoid of matrix;ii) finer grained;iii) having a higher percentage of grains with irregular and sutured contacts and iv) lesser abundance of grains displaying intra-granular deformation.
文摘Climate change can adversely impact the thermal comfort and energy efficiency of the buildings stock. The South Asian countries are particularly vulnerable to the adverse impacts of climate change specially in the form of rising temperatures and increasing frequency of heat waves. The passive building design measures can be useful in mitigating and adapting to the climate change by increasing energy efficiency and reducing greenhouse gas (GHG) emissions. In this study various passive climate change adaptation measures (PCAMs) have been used individually and in form of combinations in order to analyze their impact on the energy efficacy of residential buildings in Pakistan. It has been found that the natural ventilation and front green wall are the most efficient options for reducing the overall energy consumption. By implementation of these PCAMs, cooling demand can be decreased by 27.75% while heating demand can be reduced by 35%. Secondly, the prospect of net zero-energy building and reduced CO2 emissions are also studied. It has been shown that building can achieve net-zero energy on an annual basis at every orientation and it can attain the status of nearly zero-energy building on a monthly basis. Moreover, emitted CO2 can be reduced by 31% by using the renewable energy.
基金the National Natural Science Foundation of China(51772080,51672208,51774259,and 51402093)the Natural Science Foundation of Guangdong Province(2021A1515012356 and 2017A030313289)+4 种基金the project foundation from the Ministry of Education of Guangdong Province(2019KTSCX151)Shenzhen Government Plan of Science and Technology(JCYJ20180305125247308)the National Laboratory of Solid State Microstructures,Nanjing University,EPSRC(EP/I013229/1)Royal Society and Newton Fund(NAF\R1\191294)Key Program for International S&T Cooperation Projects of Shaanxi Province(2019JZ-20,2019KWZ-03)。
文摘Semiconductors and the associated methodologies applied to electrochemistry have recently grown as an emerging field in energy materials and technologies.For example,semiconductor membranes and heterostructure fuel cells are new technological trend,which differ from the traditional fuel cell electrochemistry principle employing three basic functional components:anode,electrolyte,and cathode.The electrolyte is key to the device performance by providing an ionic charge flow pathway between the anode and cathode while preventing electron passage.In contrast,semiconductors and derived heterostructures with electron(hole)conducting materials have demonstrated to be much better ionic conductors than the conventional ionic electrolytes.The energy band structure and alignment,band bending and built-in electric field are all important elements in this context to realize the necessary fuel cell functionalities.This review further extends to semiconductor-based electrochemical energy conversion and storage,describing their fundamentals and working principles,with the intention of advancing the understanding of the roles of semiconductors and energy bands in electrochemical devices for energy conversion and storage,as well as applications to meet emerging demands widely involved in energy applications,such as photocatalysis/water splitting devices,batteries and solar cells.This review provides new ideas and new solutions to problems beyond the conventional electrochemistry and presents new interdisciplinary approaches to develop clean energy conversion and storage technologies.
基金This work was financially supported by the University of Science and Technology of China(USTC)(No.KY2060000150)the Fundamental Research Funds for the Central Universities(No.WK2060000040).We are thankful for the support from the USTC Center for Micro and Nanoscale Research and Fabrication and the Supercomputing Center of the USTC.
文摘With the disruptive carbon cycle being blamed for global warming,the plausible electrocatalytic CO_(2)reduction reaction(CO_(2)RR)to form valuable C_(2+)hydrocarbons and feedstock is becoming a hot topic.Cu-based electrocatalysts have been proven to be excellent CO_(2)RR alternatives for high energy value-added products in this regard.However,the selectivity of CO_(2)RR to form C_(2+)products via Cu-based catalysts suffers from a high overpotential,slow reaction kinetics,and low selectivity.This review attempts to discuss various cutting-edge strategies for understanding catalytic design such as Cu-based catalyst surface engineering,tuning Cu bandgap via alloying,nanocatalysis,and the effect of the electrolyte and pH on catalyst morphology.The most recent advances in in situ spectroscopy and computational techniques are summarized to fully comprehend reaction mechanisms,structural transformation/degradation mechanisms,and crystal facet loss with subsequent effects on catalyst activity.Furthermore,approaches for tuning Cu interactions are discussed from four key perspectives:single-atom catalysts,interfacial engineering,metal-organic frameworks,and polymer-incorporated materials,which provide new insights into the selectivity of C_(2+)products.Finally,major challenges are outlined,and potential prospects for the rational design of catalysts for robust CO_(2)RR are proposed.The integration of catalytic design with mechanistic understanding is a step forward in the promising advancement of CO_(2)RR technology for industrial applications.
